Tiffen 43mm 812 Warming Filter improves skin tones and is ideal for portraits taken on a cloudy day or outdoor in shade on a sunny day. Ideal for portraits or scenics. Absorbs blue cast often caused by electronic flash. Adds warmth to pale washed-out flesh tones. Warmer results than Sky 1-A. It also absorbs approximately 85% of UV light while adding warmth to the overall scene.